Cod sursa(job #2949490)

Utilizator begusMihnea begus Data 30 noiembrie 2022 19:29:46
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.11 kb
#include <bits/stdc++.h>
using namespace std;

ifstream fin("arbint.in");
ofstream fout("arbint.out");

int n, m;

struct Node{
    int mx;
} a[400001];

void update(int pos, int val, int node=1, int st=1, int dr=n){
    if(st==dr){
        a[node].mx = val;
        return;
    }

    int mid=(st+dr)/2;
    if(pos<=mid){
        update(pos, val, node*2, st, mid);
    }else{
        update(pos, val, node*2+1, mid+1, dr);
    }

    a[node].mx = max(a[node*2].mx, a[node*2+1].mx);
}

int query(int x, int y, int node=1, int st=1, int dr=n){
    if(x>dr || y<st) return 0;
    if(x<=st && y>=dr){
        return a[node].mx;
    }

    int mid=(st+dr)/2;
    int Q_st=query(x, y, node*2, st, mid);
    int Q_dr=query(x, y, node*2+1, mid+1, dr);

    return max(Q_st, Q_dr);
}

int main(){
    fin >> n >> m;
    for(int i=1; i<=n; i++){
        int x;
        fin >> x;
        update(i, x);
    }
    while(m--){
        int c, a , b;
        fin >> c >> a >> b;
        if(c==0){
            fout << query(a, b) << '\n';
        }else{
            update(a, b);
        }
    }
}